Motor driven pool cleaning devices have been around for some time. Typically, such devices include a motor, a pump powered by the motor and a filtering system. The filtering system includes an intake, a filter and an exhaust. The pump creates suction and draws pool water containing dirt and debris into the vehicle's filter. Upon passing through the pool's filter, the pool water is sent through the exhaust cleaner than when it arrived. The pool cleaning devices travels around the pool sucking in water through the intake and exhausting cleaner water through the exhaust for a period of time determined by the user. In this way, cleanliness of the pool is maintained.
In order to travel around the pool, the typical pool cleaning device moves around on rollers. Roller drive mechanisms have advantages over wheel or tank tracks because they can run over obstacles more easily. Another advantage of using rollers is that they can be set for a wide track. A wide track has the advantage of making the cleaning device tend to run. Unfortunately, such straight tracking is also problematic. In order to properly clean the pool surface, the pool cleaning device must repeatedly change direction and even go sidewise. This has led many manufacturers of such pool cleaning devices to adopt a two motor drive system. Without two motors, external action is often required. Clearly, such two motor pool cleaning devices tend to dramatically increase costs and make such devices more complicated and consequently more unreliability.
Typically, pool cleaning devices are designed to clean the non-vertical surfaces or walls of a swimming pool, such as a pool bottom. Of course, most of the time these are precisely the areas dirt accumulates. However, all pool cleaning devices must be able to navigate vertical obstacles, such as ladders, steps or safety ledges, without being hung up and prevented from its task of pool cleaning. As is well understood in the art, pool cleaning devices are easily caught and trapped by such vertical and like obstacles.
What is needed is a single motor pool cleaning device, which is adapted to clean the entire pool while being able to overcome virtually all pool obstacles, including vertical obstacles.